Moment and Shear Force Interaction in Steel-Concrete Composite Beam by Finite Element Analysis focusing on continuous beam

Abstract

Design of large span continuous bridges and building structures supporting high magnitude concentrated loads using capacity design concept should consider the presence of shear in beams. Current Ethiopian design code (ESEN 2015) specifications for design of continuous composite beam do not fully consider effect of reduction in maximum moment capacity due to the presence of shear. This may result in the uneconomical section design. In this paper, using finite element analysis, moment-shear interaction property was investigated, shear-moment interaction curves developed and the maximum shear and moment values estimated for 21 continuous steel concrete composite beam models. Independent variables were cross-section of steel beam ௛ೢ ௧ೢ ratio values 90,120 and 150 as well as concrete slab reinforcement ratio ( 𝜌௦ ) of 0, 1%, 2.5% and 3%. Section of the beam around middle support regions were studied. Geometric non-linearity, material non linearity and full shear connection conditions were modeled. Model validation done using experimental test results obtained from literature review. Analysis results disclosed that finite element model’s maximum load value obtained was 95.6% similar with corresponding maximum load of experiment data. Under combined effect of moment and shear, 𝜌௦ of concrete slab and the ௛ೢ ௧ೢ significantly influenced the ultimate load and failure modes of composite beams, all FEA output values fall outside the moment–shear interaction curves suggested in Ethiopian Building Code. Moment–shear interaction curves varied little with the increasing of slab reinforcement ratio (𝜌௦ ) than increase in values of web cross-section slenderness ratio ( ௛ೢ ௧ೢ ).